<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    #box{
      width: 200px;
      height: 200px;
      background-color: #ae1b1b;
    }
  </style>
</head>
<body>
 
  <div id="app">
      <div id="box" v-show="isShow"></div>
  </div>
  <script src="./vue.global.js"></script>
  <script>
    const str = '这是js的变量'
    const { createApp } = Vue;
    const app = createApp({
      data(){
        return {
          isShow: false
        }
      }
    });
    app.mount('#app')
    

    
  </script>
</body>
</html>